The following U.S. patents are incorporated herein by reference:
U.S. Pat. No. 9,944,385 discloses a system for controlling trim position of a marine propulsion device on a marine vessel, which includes a trim actuator having a first end configured to couple to the marine propulsion device and a second end configured to couple to the marine vessel. A controller controls position of the trim actuator between an extended position wherein the propulsion device is trimmed up with respect to the vessel and a retracted position wherein the propulsion device is trimmed down with respect to the vessel. A shock relief mechanism overrides position control by the controller and allows extension of the trim actuator upon the occurrence of an overpressure event. An arresting mechanism, when activated, prevents extension of the trim actuator beyond a certain limit. The controller selectively activates the arresting mechanism in response to a determination that the propulsion device is being commanded in reverse. Methods for controlling trim position are also included.
U.S. Pat. No. 9,849,957 discloses a steering actuator for steering an outboard marine engine about a steering axis. The steering actuator has a housing; a piston device that is disposed in the housing, wherein hydraulic actuation of the piston device causes the outboard marine engine to pivot about the steering axis; and a valve device that is disposed in the housing. The valve device controls a flow of a hydraulic fluid to move the piston device in a first piston direction and to move the piston device in an opposite, second piston direction. Movement of the piston device in the first piston direction causes the outboard marine engine to pivot in a first pivot direction and movement of the piston device in the second piston direction causes the outboard marine engine to pivot in an opposite, second pivot direction.
U.S. Pat. No. 8,046,122 discloses a control system for a hydraulic steering cylinder that utilizes a supply valve and a drain valve. The supply valve is configured to supply pressurized hydraulic fluid from a pump to either of two cavities defined by the position of a piston within the hydraulic cylinder. A drain valve is configured to control the flow of hydraulic fluid away from the cavities within the hydraulic cylinder. The supply valve and the drain valve are both proportional valves in a preferred embodiment of the present invention in order to allow accurate and controlled movement of a steering device in response to movement of a steering wheel of a marine vessel.
U.S. Pat. No. 7,699,674 discloses a steering mechanism that connects the shaft of an actuator with a piston rod of a hydraulic cylinder and provides a spool valve in which the spool valve housing is attached to the hydraulic cylinder and the shaft of the actuator extends through a cylindrical opening in a spool of the spool valve. The connector is connectable to a steering arm of a marine propulsion device and the spool valve housing is connectable to a transom of a marine vessel.
U.S. Pat. No. 7,255,616 discloses a steering system for a marine propulsion device that eliminates the need for two support pins and provides a hydraulic cylinder with a protuberance and an opening which cooperate with each other to allow a hydraulic cylinder's system to be supported by a single pin for rotation about a pivot axis. The single pin allows the hydraulic cylinder to be supported by an inner transom plate in a manner that allows it to rotate in conformance with movement of a steering arm of a marine propulsion device.
U.S. Pat. No. 6,821,168 discloses an outboard motor having an internally contained cylinder and moveable piston. The piston is caused to move by changes in differential pressure between first and second cavities within the cylinder. By adding a hydraulic pump and a steering valve, the hydraulic steering system described in U.S. Pat. No. 6,402,577 is converted to a power hydraulic steering system by adding a hydraulic pump and a steering valve to a manual hydraulic steering system.
U.S. Pat. No. 6,402,577 discloses a hydraulic steering system in which a steering actuator is an integral portion of the support structure of a marine propulsion system. A steering arm is contained completely within the support structure of the marine propulsion system and disposed about its steering axis. An extension of the steering arm extends into a sliding joint which has a linear component and a rotational component which allow the extension of the steering arm to move relative to a moveable second portion of the steering actuator. The moveable second portion of the steering actuator moves linearly within a cylinder cavity formed in a first portion of the steering actuator.
U.S. Pat. No. 5,392,690 discloses a marine hydraulic system for operation of a power steering assembly, which includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid.